Intussusception

Section: Small bowel Curriculum: Curriculum, page 58

Definition

• A condition where a part of the intestine telescopes over itself
• Rare in adults
• Most common cause of SBO in children
• Tends to be at ileocaecal junction
• Peak at 6-9 months of age

Aetiology

• Children
  • Usually no identifiable “lead point”
    • Invariably due to lymphoid swelling
  • Associated with viral illness
    • Gastroenteritis, URTI, rotavirus vaccine
  • 12% have identifiable lead point
    • Meckel’s Diverticulum (most common)
    • Polyps
    • Peutz-Jeghers Hamartomas, Adenomas, MALT
    • Appendix
    • Neoplasm
    • Submucosal haemorrhage associated with Henoch Schonlein Purpura
      • Triad: Purpura 100%, Arthritis 80%, Abdo pain 62%
    • Foreign body
    • Ectopic pancreatic or gastric tissue
    • Intestinal duplication
• Adults
  • Always from a lead point

Presentation

• Triad - pain, blood in stool, palpable mass
• Episodic severe, crampy pain, draw legs up
• Become lethargic
• Vomiting is universal, but quiet between
• Frequent bowel motions initially, may progress to currant jelly stool
• Abdominal mass may be palpated (“sausage”)

Investigations

• Plain AXR
  • Mass
  • Sparse colonic gas
  • Complete distal SBO
• USS
  • Target sign on transverse bowel view
  • “Pseudo-kidney” longitudinally

Management

Non-Operative

• Pneumatic reduction with air or CO2
  • Most common
  • Pressure 100-120mmHg
  • fluoroscopic guidance
  • 85% success
  • <1% perforation risk
• Hydrostatic reduction by enema
  • Contraindications:
    • Peritonitis
    • Haemodynamic instability
    • Entirely within small bowel unlikely to be reached
• 80% success, 11% recurrence, usually within 24 hours
• Attempt another reduction (air / H2O enema)
• Third reduction = Surgery

Operative

• For peritonitis or necrotic bowel
• Laparoscopy may confirm and may facilitate reduction
  • Can localize incision and deliver the intussusceptum from the intussuscipiens
  • Squeeze mass retrograde from distal to proximal until reduced
  • May need warm packs and observation
  • Perform appendicectomy
  • Lymphoid tissue is always inflamed and thickened around ileum (confused with tumour)
• Resection if:
  • Can’t reduce
  • Uncertain viability
  • Lead point (ileocolectomy with primary anastomosis)
  • ALWAYS in an adult